Couldn't an old coffee can produce almost the same effect?
The shape of the Vortex is what makes it different than just a coffee can. When running it hot, it's a conical reducer (more air can come in than can go out which projects the heat). When the coals are outside of the vortex, it's angle deflects heat away-and-up for a true indirect cook.
As for an old galvanized (yikes) beer bucket, the Vortex is American made 20 gauge 304 grade stainless steel.